Ethernet/IP Is Power On & Is Normal Mode Bit Behavior

V5.13.0

I’m trying to use Ethernet/IP Implicit I/O data to figure out the status of the controller, but I’m running into some issues. Most notably is the behavior of the PW (Is Power On) T (Robot) → O (PLC) bit 128.

I would expect this bit to come on when the arm is powered ON, meaning has gone through the complete initialization sequence all the way to robot operational, but the bit pulses when the arm is in the booting stage, and latches on when the robot active stage is Idle (yellow) before the last two initialization steps of brake release and robot operational are complete. The Is Normal Mode bit is also on at this point, despite the arm not being moveable at all.

If you try to start a program before brake release and robot operational are complete, you get the warning message that robot needs to be powered ON to proceed, so what is the Is Power On bit over Ethernet/IP actually telling you? Is there a different combination of bits I should be using to let me know the controller is ready to start a program?

The Is Arm Power On bit also maintains during an emergency stop condition, is this intended operation?

Hello, the terminology is a bit poorly defined. The PW bit is checking whether the arm is receiving electricity and the microcontrollers within it are booted up. It is not checking whether the brake release process has completed. To get the data you’re looking for, I recommend checking the Robot Mode integer register instead. You’ll want to wait until Robot Mode is reporting a value of 7.

The robot modes are defined on page 27 of our Client Interface document located here: https://s3-eu-west-1.amazonaws.com/ur-support-site/16496/ClientInterfaces_Primary.pdf

There are multiple types of safety stops; an Emergency Stop maintains power to the arm while engaging the brakes. Therefore, it is expected behavior for the PW bit to remain high during an Emergency Stop.